As it has become evident that lipoperoxide (peroxylipid) formation in the body and concomitant radical reactions have various harmful effects on the living body through membrane disorders, enzymatic disorders, etc., various attempts to use antioxidants and lipoperoxide formation inhibitors as medicines have been made. At present, the main lipoperoxide formation inhibitors used in the field of medicine are derivatives of natural antioxidants such as vitamin C, vitamin E, etc., and phenol derivatives (Kenji Fukuzawa, The Japanese Journal of Clinical Medicine, 46, 2269-2276, 1988). However, these compounds are not necessarily satisfactory for practical use.
It is believed that the entry of sodium ions through sodium channels into cells results in cell death or tissue damage. It is reported that tetrodotoxin, a sodium channel blocker, relieves such damage. However tetrodotoxin cannot be used for therapy because it is highly toxic (Neurosci. Lett., Vol. 121, pp. 251-254 (1991)).
U.S. Pat. No. 5,059,627 discloses a quinone or hydroquinone compound having nerve growth factor secretion inducing activity. However, this literature fails to specifically disclose a quinone or hydroquinone compound containing 2- or 3-(optionally substituted hydroxy)alkyl or (optionally substituted amino)alkyl on the quinone nucleus, or its lipoperoxide formation inhibitory effect.
Free Radical Biology & Medicine, Vol. 19, No. 2, pp. 197-207 (1995) discloses 2-(3-hydroxy-3-methylbutyl)-3,5,6-trimethyl-1,4-benzoquinone or its hydroquinone derivative. However, this literature fails to specifically discloses a quinone or hydroquinone compound containing (optionally substituted amino)alkyl on the quinone nucleus, or its lipoperoxide formation inhibitory effect.
In view of the above, the main object of the present invention is to provide a novel quinone or hydroquinone compound having excellent lipoperoxide formation inhibitory effect and sodium channel blocking effect, an industrially advantageous process for producing it, and a pharmaceutical composition containing it as an active ingredient.